I'm going to be getting the QSC PLX 2402. I already have an IAmp 600 and a Sansamp RBI. Would the RBI be enough on its own to drive the QSC? I will be feeding 2 4ohms cab. Of course this would be ideal for lugging purposes. If I really am aiming for an Ampeg sound...with limited money, is there another solution to getting closer to the sound I want with another pre amp that I can use alone instead of the iAmp w/RBI thru effects loop?